Preface Introduction 1. Fluid field equations and modal analysis in rigid containers 2. Linear forced sloshing 3. Viscous damping and sloshing suppression devices 4. Weakly nonlinear lateral sloshing 5. Equivalent mechanical models 6. Parametric sloshing (Faraday's waves) 7. Dynamics of liquid sloshing impact 8. Linear interaction of liquid sloshing with elastic containers 9. Nonlinear interaction under external and parametric excitations 10. Interactions with support structures and tuned sloshing absorbers 11. Dynamics of rotating fluids 12. Microgravity sloshing dynamics Bibliography Index.

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Liquid Sloshing Dynamics

This paper introduces and reviews the theme of laboratory testing of structures under dynamic loads. The emphasis is on the simulation of earthquake effects, for which three principle methods are discussed: shaking tables, pseudo–dynamic testing and real–time testing. The latest developments in these areas are discussed in depth in the subsequent papers in this issue. While shaking tables and pseudo–dynamic methods are quite well established, both techniques have undergone significant advances in recent years, including improvements in control to ensure accurate reproduction of dynamic loads, and the construction of very large facilities aimed at eliminating the significant scaling problems. Development of the substructuring method has enabled large–scale pseudo–dynamic tests of parts of structures, coupled to numerical models of the remainder. Attempts are now being made to extend this approach to shaking tables. Recently, considerable efforts have been devoted to methods of testing both at large scale and in real time. Two approaches are discussed: the real–time substructure method, in which a physical test and a numerical model interact in real time; and effective force testing, in which equivalent seismic forces are applied by actuators operating under force control. Both methods have been shown to be feasible, but require further development. Although the techniques described have been developed primarily for seismic testing of structures, there is considerable potential for their application to other load types in the fields of civil and mechanical engineering.

Laboratory testing of structures under dynamic loads: an introductory review

Dynamic testing of structures and components in the laboratory to determine their mechanical properties is an essential part of engineering research and development. Test apparatus of increasing sophistication has been designed over the past few decades to replicate real-world forces and motions within the laboratory environment. Accurate control of actuators is vital to the effectiveness of such apparatus, and a variety of closed- and open-loop control algorithms has been developed to address this need. The present paper reviews algorithms that are currently used in the testing industry, as well as those which are the subject of academic and industrial research. The techniques are presented in an analytical framework. As both the required forces and frequency range are often high, electrohydraulic actuation is typically used, and discussion is restricted to this area. Most examples are from the automotive industry or civil engineering field.

Control techniques for structural testing: A review

A series of full-scale shaking table tests are conducted using the E-Defense shaking table facility on a base-isolated four-story RC hospital structure. A variety of furniture items, medical appliances, and service utilities are placed on the hospital specimen in as realistic a manner as possible. Four ground motions are adopted, including recorded near-fault ground motions and synthesized long-period, long-duration ground motions. The test results show that the base-isolated system performed very effectively against near-fault ground motions due to significant reduction in the floor acceleration response, and operability and functionality of the hospital service is improved significantly as compared with the case observed for the corresponding base-fixed system. Against the long-period ground motion, however, the hospital service is difficult to maintain, primarily because of the significant motion of furniture items and medical appliances supported by casters. Resonance accentuated large displacements and velocities on the floors of the base-isolated system, which causes such furniture items and medical appliances to slide, sometimes more than 3 m, resulting in occasional collision with other furnitures or against the surrounding partition walls. It is notable that a key to maintaining the function of the medical facilities is to securely lock the casters of furniture and medical appliances. Copyright © 2011 John Wiley & Sons, Ltd.

Full-scale shaking table test for examination of safety and functionality of base-isolated medical facilities

SUMMARY

Base isolation is a well known technology that has been proven to reduce structural response to horizontal ground accelerations. However, vertical response still remains a topic of concern for base-isolated buildings, perhaps more so than in fixed-base buildings as isolation is often used when high performance is required. To investigate the effects of vertical response on building contents and nonstructural components, a series of full-scale shaking table tests were conducted at the E-Defense facility in Japan. A four-story base-isolated reinforced concrete building was outfitted as a medical facility with a wide variety of contents, and the behavior of the contents was observed. The rubber base isolation system was found to significantly amplify vertical accelerations in some cases. However, the damage caused by the vertical ground motions was not detrimental when peak vertical floor accelerations remained below 2 g with three exceptions: (1) small items placed on shelves slid or toppled; (2) objects jumped when placed on nonrigid furniture, which tended to increase the response; and (3) equipment with vertical eccentricities rocked and jumped. In these tests, all equipment and nonstructural components remained functional after shaking. Copyright © 2013 John Wiley & Sons, Ltd.

Full‐scale shaking table test of a base‐isolated medical facility subjected to vertical motions

In 1995 the great Hanshin–Awaji earthquake disaster occurred in the Japanese city of Kobe and its vicinity, and more than 6000 people were killed as a result of the collapse of buildings. This was a clear demonstration of how very strong ground motion in the area near a seismic fault can cause severe structural damage beyond that which is usually estimated. It also emphasized the importance of earthquake engineering research in solving such problems as why and how structures collapse in real conditions. In response to this disaster, the National Research Institute for Earth Science and Disaster Prevention (NIED) and the Science and Technology Agency of the Japanese Government (STA) planned to build a three–dimensional, full–scale, earthquake–testing facility as one of the core research facilities for earthquake disaster prevention. It is hoped to be able to carry large–scale structures and to simulate the process of dynamic collapse using three–dimensional, strong earthquake motion. For this purpose, the NIED and the STA began to develop large actuators and related components in 1995 and completed them in 1998. Through this development and testing, the design and manufacturing techniques of a large actuator system were successfully achieved. After that, the NIED and the STA began the design and construction of the new facility in the fiscal year of 1998. The construction work is now in progress in Miki City, near Kobe, Japan. It is scheduled to be completed by the beginning of 2005. In this paper, we summarize the performance and features of this new facility and the results of the technical developments.

Construction of a three–dimensional, large–scale shaking table and development of core technology

This report deals with the experimental study of seismic response behavior of piping systems in the industrial facilities such as petro-chemical plants and nuclear power plants. Special attention is focussed on the nonlinear dynamic response of piping systems due to frictional vibration appeared among piping and supporting devices. 3 dimensional mock-up piping model having 30 m Iength and 8 inches diameter is excited by large scale (15 m x 15 m) shaking table. Power spectra of the response vibration and loading-response relations in the form of hysteresis loop under several excitation levels are calculated. Response reduction effect caused by frictional vibration is evaluated and demonstrated in terms of "response reduction factor". Numerical simulation by use of nonlinear simplified friction model is also performed and calculated piping response is compared with those from vibration tests.

Vibration test of plant piping system having friction support

After the great Hanshin-Awaji earthquake disasetr, the National Research Institute for Earth Science and Disaster Prevention (NIED) and the Science and Technology Agency of the Japanese Government (STA) planned to build a three-dimensional, full-scale, earthquake-testing facility (E-Defense) as one of the core research facilities for earthquake disaster prevention. It is hoped to be able to carry large-scale structures and to simulate the process of dynamic collapse using three-dimensional, strong earthquake records. For this purpose, the NIED has developed large actuators and related components from 1995 and completed them in 1998. After that, the NIED and the STA began the design and construction of the new facility in the fiscal year of 1998, and now, the construction work is in final stage at Miki City, near Kobe, Japan. It is scheduled to complete by the beginning of 2005. In this paper, the basic performance and features of this new facility and the outline of recent construction work are summarized.

https://www.jaee.gr.jp/stack/submit-j/v04n03/data/pdf/9-1.pdf

Construction of a 3-d full-scale earthquake testing facility

Some tanks have been damaged at the roofs due to sloshing impact caused by strong earthquakes. It is, therefore, necessary to consider the impact force in the aseismic design code for tank roofs. However, there are few studies on the earthquake responses of storage and process tank roofs. As a first step to investigate the effects of sloshing impact a series of the shaking table tests of a rectangular tank have been conducted at the National Research Institute for Earth Science and Disaster Prevention (NIED). The results of these shaking table tests are presented in the paper. The test tank is rectangular in shape having dimensions of 5 m {times} 3 m {times} 2 m length {times} width {times} height). The tank was constructed of glass-fiber reinforced plastic panels. Every panel had a flange on four edges, and each panel was connected by bolts along the flange. The test tank was set on the NIED shaking table (15 m by 15 m). Two types of liquid were used, water and a viscous liquid (water mixed with polymeric powders). The roof impact pressures and other quantities were measured. During the tests using the 400 pi El-Centro excitation, the roof deformation sensormore » steel beam was damaged. The response of side walls with different rigidity were measured in the wall bulging tests. The measured vibrations within the panel plates were larger than those in the panel flanges. The viscous liquid of 100 cp had little influence on wall bulging responses. However, the viscous effects on sloshing responses were observed in the sloshing tests. Approximate analyses of rectangular tanks, considering the influence of static water pressure, are also presented in this paper.« less

Nobuyuki Ogawa

Papers

Construction of a three–dimensional, large–scale shaking table and development of core technology

Vibration test of plant piping system having friction support

Construction of a 3-d full-scale earthquake testing facility

Sloshing roof impact tests of a rectangular tank

World's Largest Shaking Table Takes Shape in Japan - A Summary of Construction Plan and Technical Development